Answer:
A person's hand holding a cold pack on an ankle ... To determine if a reaction is exothermic or endothermic, you have to compare the ... Well, that also applies to energy of solution problems.
Explanation:
Explanation:
- The rule apply for the multiplication and division is :
The least number of significant figures in any number of the problem determines the number of significant figures in the answer.
- The rule apply for the addition and subtraction is :
The least precise number present after the decimal point determines the number of significant figures in the answer.
a) 12.3 mm × 15.853 mm :
Three significant figures.
b) 72.98 · 15.830 ml
Three significant figures.
c) 12.3 mm + 15.853 mm
Three significant figures.
d) 172.3 cm - 15.853 cm
Four significant figures.
<span>The difference between heterogeneous and homogeneous mixtures is the degree at which the materials are mixed together and the uniformity of their composition. Ahomogeneous mixture is a mixture where the components that make up the mixtureare uniformly distributed throughout the mixture.</span>
Answer:
C, 3.00 moles
Explanation:
First, balance the equation.
4Al + 3O2 ---> 2Al2O3
From the balanced equation, assuming Al is limiting, the mole ratio of Al:Al2O3 = 4:2 = 2:1,
meaning every 2 moles of Al used, produces 1 mole of Al2O3.
So, since 1.5 moles of Al2O3 is produced,
the no. of moles of Al used = 1.5 x2
= 3.0 moles
= C
Answer:
The relative number of products and reactants
Explanation:
- The numerical coefficients in chemical equations show the ratio of the molecules of each substance involved in a chemical reaction that is both reactants and products.
- The coefficients in a balanced chemical equation indicate the relative number of moles of reactants and products.
- Additionally, coefficients are important to prove the law of conservation of mass.